Frutti di mare with saffron fregola

Ingredients

• 600g/1lb 5oz shell-on prawns
• 4 tbsp olive oil
• 300ml/10fl oz fish stock
• 500g/1lb 2oz fregola
• 1 onion, finely chopped
• 2 garlic, finely chopped
• 1 red chilli, finely chopped or ½ tsp dried red chilli flakes
• sprig thyme
• 1 tsp dried oregano
• pinch ground saffron
• 100ml/3½fl oz white wine or vermouth
• 4 medium tomatoes, skinned and roughly chopped
• 200g/7oz clams, cleaned
• 200g/7oz mussels, cleaned and beards removed
• 12 small scallops
• small bunch basil, leaves only
• small bunch parsley, leaves only
• lemon wedges